The NEID spectrometer is an optical (380-930 nm), fiber-fed, precision Doppler spectrometer currently in de- velopment for the WIYN 3.5 m telescope at Kitt Peak National Observatory as part of the NN-EXPLORE partnership. Designed to achieve a radial velocity precision of &lt; 30 cm/s, NEID will be sensitive enough to detect terrestrial-mass exoplanets around low-mass stars. Light from the target stars is focused by the telescope to a bent Cassegrain port at the edge of the primary mirror mechanical support. The specialized NEID “Port Adapter” system is mounted at this bent Cassegrain port and is responsible for delivering the incident light from the telescope to the NEID fibers. In order to provide stable, high-quality images to the science instrument, the Port Adapter houses several sub-components designed to acquire the target stars, correct for atmospheric dis- persion, stabilize the light onto the science fibers, and calibrate the spectrometer by injecting known wavelength sources such as a laser frequency comb. Here we provide an overview of the overall opto-mechanical design and system requirements of the Port Adapter. We also describe the development of system error budgets and test plans to meet those requirements.

PANOPTES is a citizen-science based project to discover exoplanets with consumer cameras. It is open source and aims to be highly efficient at collecting photometric data by running a wide field survey using DSLR cameras and standard lenses. In the two years since the demonstration of the baseline design at SPIE 2016 the project has moved forward in getting the hardware design ready for citizen scientists and data analysis, benefiting from an influx of both professional and amateur support. At the same time the project has experienced a number of challenges related to the nature of a grassroots project with no specific institutional home. Here we present a status update to the project with a focus on the issues associated with creating, and maintaining, a successful “pro-am” astronomy project.
This talk will specifically focus on a couple of keys concepts related to the operation of PANOPTES as a distributed observatory built by a collection of professional and amateur astronomers. These concepts can largely be broken down as: software; hardware; and organizational. However, a central theme of the talk will also be the fact that PANOPTES operates without a centralized institution, which means that decisions related to software and hardware are necessarily tied into the organizational decisions. Likewise, since the project has no official operating budget but operates largely off the budgets of each individual team (in addition to a NASA/JPL grant, the attainment of which will also be discussed), the hardware decisions and the evolving landscape of commercial over-the-counter (COTC) hardware play a significant role in the operation and maintenance of the project as a whole, which in turn affects how the software is developed.
Through all of these areas PANOPTES has experienced successes and failures as well as simple deviations from original plans. As a project we have benefited enormously from the donation of time and storage on the Google Cloud Platform (GCP), allowing us to explore technologies and solutions that would otherwise be unfeasible, but as an unofficial project we have been unable to secure a permanent formal agreement with GCP, creating challenges related to the long-term viability of those software solutions.
Being a unique project that aims to be as scientifically productive as it is successful as an outreach tool, it is hoped that the talk will provide some valuable learned lessons for any future projects that hope to utilize the unique professional-amateur dynamic that exists within the field of astronomy and open-source software.

One of the most useful techniques in astronomical instrumentation is image slicing. It enables a spectrograph to have a more compact angular slit, whilst retaining throughput and increasing resolving power. Astrophotonic components like the photonic lanterns and photonic reformatters can be used to replace bulk optics used so far. This study investigates the performance of such devices using end-to-end simulations to approximate realistic on-sky conditions. It investigates existing components, tries to optimize their performance and aims to understand better how best to design instruments to maximize their performance. This work complements the recent work in the field and provides an estimation for the performance of the new components.

Ever more precise radial velocity instruments are needed to observe potential earth-like exoplanet targets that are beyond the range of current generation high resolution echelle spectrographs. Meanwhile, extreme adaptive optics systems at 8 meter class facilities have made ground based observations possible at the diffraction limit. In the field of Doppler spectroscopy, one way to take advantage of these AO capabilities is by the development of ultra-stable single mode fiber fed spectrographs.1 Coupling the light efficiently into SMFs with an extreme adaptive optics system offers significant advantage in removing modal noise, reducing instrument size, enabling superior environmental control and curbing cost. We report the design and challenges in building an ultra-stable spectrograph for the near infrared range. The design wavelength range is 650 to 1500 nm.

The Habitable-Zone Planet Finder (HPF) is a stabilized, fiber-fed, NIR spectrometer recently commissioned at the 10m Hobby-Eberly telescope (HET). HPF has been designed and built from the ground up to be capable of discovering low mass planets around mid-late M dwarfs using the Doppler radial velocity technique. Novel apects of the instrument design include mili-kelvin temperature control, careful attending to fiber scrambling, and optics, mounting and detector readout schemes designed to minimize drifts and maximize the radial velocity precision. The optical design of the HPF is an asymmetric white pupil spectrograph layout in a vacuum cryostat cooled to 180 K. The spectrograph uses gold-coated mirrors, a mosaic echelle grating, and a single Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7-micron cutoff covering parts of the information-rich z, Y and J NIR bands at a spectral resolution of R~55,000. The use of 1.7 micron H2RG enables HPF to operate warmer than most other cryogenic instruments- with the instrument operating at 180K (allowing normal glasses to be used in the camera) and the detector at 120K. We summarize the engineering and commissioning tests on the telescope and the current radial velocity performance of HPF. With data in hand we revisit some of the design trades that went into the instrument design to explore the remaining tall poles in precision RV measurements in the near-infrared. HPF seeks to extend the precision radial velocity technique from the optical to the near-infrared, and in this presentation, we seek to share with the community our experience in this relatively new regime.

RHEA is a compact high-resolution single-mode spectrograph that can easily be produced in larger quantities as budgets allow. The instrument will be housed in a temperature-stabilized vacuum chamber which is surrounded by several layers of thermal shielding. The optical design employs cost-effective commercially available compo- nents, a cooled CMOS detector, and a double-fiber input which permits simultaneous wavelength calibration.

NEID is a new extreme precision Doppler spectrometer for the WIYN telescope. It is fiber fed and employs a classical white pupil Echelle configuration. NEID has a fiber aperture of only 0.92” on sky in high-resolution mode, and its tight radial velocity error budget resulted in very stringent stability requirements for the input illumination of the spectrograph optics. Consequently, the demands on the fiber injection are challenging. In this paper, we describe the layout and optical design of the injection module, including a broadband, high image quality relay and a high-performance atmospheric dispersion corrector (ADC) across the bandwidth of 380 – 930 nm.

Precise wavelength calibration is a persistent problem for highest precision Doppler spectroscopy. The ideal calibrator provides an extremely stable spectrum of equidistant, narrow lines over a wide bandwidth, is reliable over timescales of years, and is simple to operate. Unlike traditional hollow cathode lamps, etalons provide an engineered spectrum with adjustable line distance and width and can cover a very broad spectral bandwidth. We have shown that laser locked etalons provide the necessary stability with an ideal spectral format for calibrating precision Echelle spectrographs, in a cost-effective and robust package. Anchoring the etalon spectrum to a very precisely known hyperfine transition of rubidium delivers cm/s-level stability over timescales of years. We have engineered a fieldable system which is currently being constructed as calibrator for the MAROON-X, HERMES, KPF, FIES and iLocater spectrographs.

NEID is an ultra-stabilized, high-resolution, fiber-fed, spectrometer being built by a multi-institutional team for the 3.5 m WIYN telescope at Kitt Peak National Observatory, with a delivery date in 2019. The instrument is supported by the NN-EXPLORE program, a joint endeavor between NASA and the NSF to provide the exoplanet community with extreme ground-based Doppler radial velocity (RV) measurement capability. NEID's primary science objective is the discovery and characterization of terrestrial mass exoplanets, including follow-up of planets discovered by TESS and other spacecraft missions. Achieving these goals requires a multi-faceted approach that combines a state of the art Doppler instrument with a RV precision goal of 30 cm/s, a significantly improved understanding of the stellar radial velocity signal and intrinsic stellar variability, and large numbers of observations distributed optimally in time following guidelines refined over the past 25 years of RV exoplanet discovery.
NEID uses a single-arm white pupil echelle optical design to produce R~100,000 spectra covering the complete wavelength range from 0.38 - 0.92 microns on a single 9k x 9k CCD. The optical bench and optics are stabilized with a state of the art temperature control system that achieves sub-mK stability, and are surrounded by a vacuum chamber that maintains 10^-7 Torr pressure or better. This extreme stability minimizes drift in the optics and optomechanical systems. Light is transfered from the telescope to the spectrometer using fiber-optic feeds that combine circular and octagonal fibers with a ball-lens double scrambler to provide high amounts of radial and azmuthal scrambling that minimize variations in the input illumination. These fibers interface with the WIYN telescope through a sophisticated new instrument port, which will provide atmospheric-dispersion correction and active tip-tilt to ensure precise and repeatable target positioning on the fiber. A three tiered calibration system utilizes a Laser Frequency Comb as the primary wavelength calibrator, while providing a stabilized etalon and ThAr and UNe Hollow-Cathode Lamps as high-reliability backup sources. An integrated exposure meter in the form of a low-resolution spectrometer measures precise chromatic exposure time centroids. A sophisticated data reduction pipeline that builds upon algorithms developed over decades of precision RV spectroscopy will automatically transform raw images and telemetry into RVs and other high-level data products, which will be served to users and the community through a NExScI portal.
In this paper, we will provide an overview of the NEID project, including a progress update on the instrument integration and testing. We will also describe the WIYN operations plan, which is built around queue scheduled observations, and detail notional science programs that can be carried out with NEID, including the instrument team's GTO program. Finally, we will briefly discuss the impacts of stellar variability, which currently limit RV measurement precision well shy of the fundamental instrument limit, and which we and others are actively working to better understand and mitigate. Additional papers in this conference will describe the instrument subsystems in more detail.

The NEID Port Adapter is the interface between the WIYN 3.5m Telescope and the NEID fiber-fed spectrometer. The spectrometer requires the stellar jitter to be controlled for 90% of the time to within 50 milli-arc seconds for visual magnitudes 12, and 200 milli-arc seconds for V-magnitudes 12-16. The NEID Port Adapter will use an Andor EMCCD with 13 micron pixels, and a tip/tilt piezo stage from nPoint with a lowest resonant mode of 479 Hz. We expect to meet the requirement with a closed-loop rate of 27 Hz. We have data taken at the WIYN telescope consisting of stellar centroids captured at a rate of 108.75 Hz, which we rebin to test the response at lower sampling rates. We present the results of feeding these waveforms into the nPoint controller and measuring the actual response.

We report on the upgrade of the fiber link of FIES, the high-resolution echelle spectrograph at the Nordic Optical Telescope (NOT). In order to improve the radial velocity (RV) stability of FIES, we replaced the circular fibers by octagonal and rectangular ones to utilize their superior scrambling performance. Two additional fibers for a planned polarimetry mode were added during the upgrade. The injection optics and the telescope front-end were also replaced. The first on-sky RV measurements indicate that the influence of guiding errors is greatly suppressed, and the overall RV precision of FIES has significantly improved.

The Keck Planet Finder (KPF) is a fiber-fed, high-resolution, high-stability spectrometer in development for the W.M. Keck Observatory. The instrument recently passed its preliminary design review and is currently in the detailed design phase. KPF is designed to characterize exoplanets using Doppler spectroscopy with a single measurement precision of 0.5 m s<sup>−1</sup> or better; however, its resolution and stability will enable a wide variety of other astrophysical pursuits. KPF will have a 200 mm collimated beam diameter and a resolving power greater than 80,000. The design includes a green channel (445 nm to 600 nm) and red channel (600 nm to 870 nm). A novel design aspect of KPF is the use of a Zerodur optical bench, and Zerodur optics with integral mounts, to provide stability against thermal expansion and contraction effects.

VELOCE is an IFU fibre feed and spectrograph for the AAT that is replacing CYCLOPS2. It is being constructed by the AAO and ANU. In this paper we discuss the design and engineering of the IFU/fibre feed components of the cable. We discuss the mode scrambling gain obtained with octagonal core fibres and how these octagonal core fibres should be spliced to regular circular core fibres to ensure maximum throughput for the cable using specialised splicing techniques. In addition we also describe a new approach to manufacturing a precision 1D/2D array of optical fibres for some applications in IFU manufacture and slit manufacture using 3D printed fused silica substrates, allowing for a cheap substitute to expensive lithographic etching in silicon at the expense of positional accuracy. We also discuss the Menlo Systems laser comb which employs endlessly-singlemode fibre to eliminate modal noise associated with multimode fibre transmission to provide the VELOCE spectrograph with a stable and repeatable source of wavelength calibration lines.

High precision Doppler observations of bright stars can be made efficiently with small aperture telescopes. We are constructing a high resolution echelle spectrograph for the new 0.6 m telescope at Central Washington University. The spectrograph is fed by a multimode fiber and operates in the visible wavelength range of 380-670 nm. The spectrograph uses a white pupil design with 100 mm beam diameter and a monolithic R4 echelle grating.

RHEA is a single-mode ´echelle spectrograph designed to be a replicable and cost effective method of undertaking precision radial velocity measurements. The instrument has a novel fiber feed with an integral field unit injecting into a grid of single-mode fibers reformatted to form a pseudo-slit, increasing throughput and enabling highspatial resolution observations when operating behind Subaru and the SCExAO adaptive optics system. The past 18 months have seen a replacement cable constructed for the instrument to address modal noise caused by closely packed fibers with similar path lengths. Here we detail the cable fabrication procedure, design improvements, increased precision in meeting the required sub-micron optical tolerances, throughput gains, and known remaining issues.

Veloce is an ultra-stable fibre-fed R4 echelle spectrograph for the 3.9 m Anglo-Australian Telescope. The first channel to be commissioned, Veloce ‘Rosso’, utilises multiple low-cost design innovations to obtain Doppler velocities for sun-like and M-dwarf stars at &lt;1 ms <sup>-1</sup> precision. The spectrograph has an asymmetric white-pupil format with a 100-mm beam diameter, delivering R&gt;75,000 spectra over a 580-930 nm range for the Rosso channel. Simultaneous calibration is provided by a single-mode pulsed laser frequency comb in tandem with a traditional arc lamp. A bundle of 19 object fibres ensures full sampling of stellar targets from the AAT site. Veloce is housed in dual environmental enclosures that maintain positive air pressure at a stability of &plusmn;0.3 mbar, with a thermal stability of &plusmn;0.01 K on the optical bench. We present a technical overview and early performance data from Australia's next major spectroscopic machine.

MAROON-X is a red-optical, high precision radial velocity spectrograph currently nearing completion and undergoing extensive performance testing at the University of Chicago. The instrument is scheduled to be installed at Gemini North in the first quarter of 2019. MAROON-X will be the only RV spectrograph on a large telescope with full access by the entire US community. In these proceedings we discuss the latest addition of the red wavelength arm and the two science grade detector systems, as well as the design and construction of the telescope front end. We also present results from ongoing RV stability tests in the lab. First results indicate that MAROON-X can be calibrated at the sub-m s<sup>−1</sup> level, and perhaps even much better than that using a simultaneous reference approach.

We report on the construction and testing of a vacuum-gap Fabry–Pérot etalon calibrator for high precision radial velocity spectrographs. Our etalon is traced against a rubidium frequency standard to provide a cost effective, yet ultra precise wavelength reference. We describe here a turn-key system working at 500 to 900 nm, ready to be installed at any current and next-generation radial velocity spectrograph that requires calibration over a wide spectral bandpass. Where appropriate, we have used off-the-shelf, commercial components with demonstrated long-term performance to accelerate the development timescale of this instrument. Our system combines for the first time the advantages of passively stabilized etalons for optical and near-infrared wavelengths with the laser-locking technique demonstrated for single-mode fiber etalons. We realize uncertainties in the position of one etalon line at the 10 cm s−1 level in individual measurements taken at 4 Hz. When binning the data over 10 s, we are able to trace the etalon line with a precision of better than 3 cm s−1. We present data obtained during a week of continuous operation where we detect (and correct for) the predicted, but previously unobserved shrinking of the etalon Zerodur spacer corresponding to a shift of 13 cm s−1 per day.

We present preliminary results for the environmental control system from NEID, our instrument concept for NASA's Extreme Precision Doppler Spectrograph, which is now in development. Exquisite temperature control is a requirement for Doppler spectrographs, as small temperature shifts induce systematic Doppler shifts far exceeding the instrumental specifications. Our system is adapted from that of the Habitable Zone Planet Finder instrument, which operates at a temperature of 180K.We discuss system modifications for operation at T ~ 300K, and show data demonstrating sub-mK stability over two weeks from a full-scale system test.

The Replicable High-resolution Exoplanet and Asteroseismology (RHEA) spectrograph is being developed to serve as a basis for multiple copies across a network of small robotic telescopes. The spectrograph operates at the diffraction-limit by using a single-mode fiber input, resulting in a compact and modal-noise-free unit. The optical design is mainly based on off-the-shelf available components and comprises a near-Littrow configuration with prism cross-disperser. The échelle format covers a wavelength range of 430-650 nm at R=75,000 resolving power. In this paper we briefly summarize the current status of the instrument and present preliminary results from the first on-sky demonstration of the prototype using a fully automated 16" telescope, where we observe stable and semi-variable stars up to V=3.5 magnitude. Future steps to enhance the efficiency and passive stability of RHEA are discussed in detail. For example, we show the concept of using a multi-fiber injection unit, akin to a photonic lantern, which not only enables increased throughput but also offers simultaneous wavelength calibration.

The Waltz Spectrograph is a fiber-fed high-resolution échelle spectrograph for the 72 cm Waltz Telescope at the Landessternwarte, Heidelberg. It uses a 31.6 lines/mm 63.5&deg; blaze angle échelle grating in white-pupil configuration, providing a spectral resolving power of R ~ 65,000 covering the spectral range between 450-800nm in one CCD exposure. A prism is used for cross-dispersion of échelle orders. The spectrum is focused by a commercial apochromat onto a 2k&times;2k CCD detector with 13.5&mu;m per pixel. An exposure meter will be used to obtain precise photon-weighted midpoints of observations, which will be used in the computation of the barycentric corrections of measured radial velocities. A stabilized, newly designed iodine cell is employed for measuring radial velocities with high precision. Our goal is to reach a radial velocity precision of better than 5 m/s, providing an instrument with sufficient precision and sensitivity for the discovery of giant exoplanets. Here we describe the design of the Waltz spectrograph and early on-sky results.

We describe a detailed radial velocity error budget for the NASA-NSF Extreme Precision Doppler Spectrometer instrument concept NEID (NN-explore Exoplanet Investigations with Doppler spectroscopy). Such an instrument performance budget is a necessity for both identifying the variety of noise sources currently limiting Doppler measurements, and estimating the achievable performance of next generation exoplanet hunting Doppler spectrometers. For these instruments, no single source of instrumental error is expected to set the overall measurement floor. Rather, the overall instrumental measurement precision is set by the contribution of many individual error sources. We use a combination of numerical simulations, educated estimates based on published materials, extrapolations of physical models, results from laboratory measurements of spectroscopic subsystems, and informed upper limits for a variety of error sources to identify likely sources of systematic error and construct our global instrument performance error budget. While natively focused on the performance of the NEID instrument, this modular performance budget is immediately adaptable to a number of current and future instruments. Such an approach is an important step in charting a path towards improving Doppler measurement precisions to the levels necessary for discovering Earth-like planets.

We have developed an optical design for a high resolution spectrograph in response to NASA’s call for an extreme precision Doppler spectrometer (EPDS) for the WIYN telescope. Our instrument covers a wavelength range of 380 to 930 nm using a single detector and with a resolution of 100,000. To deliver the most stable spectrum, we avoid the use of an image slicer, in favor of a large (195 mm diameter) beam footprint on a 1x2 mosaic R4 Echelle grating. The optical design is based on a classic white pupil layout, with a single parabolic mirror that is used as the main and transfer collimator. Cross dispersion is provided by a single large PBM2Y glass prism. The refractive camera consists of only four rotationally symmetric lenses made from i-Line glasses, yet delivers very high image quality over the full spectral bandpass. We present the optical design of the main spectrograph bench and discuss the design trade-offs and expected performance.

We present recent long-term stability test results of the cryogenic Environmental Control System (ECS) for the Habitable zone Planet Finder (HPF), a near infrared ultra-stable spectrograph operating at 180 Kelvin. Exquisite temperature and pressure stability is required for high precision radial velocity (&lt; 1m=s) instruments, as temperature and pressure variations can easily induce instrumental drifts of several tens-to-hundreds of meters per second. Here we present the results from long-term stability tests performed at the 180K operating temperature of HPF, demonstrating that the HPF ECS is stable at the 0:6mK level over 15-days, and &lt;10<sup>-7</sup> Torr over months.

The RHEA Spectrograph is a single-mode echelle spectrograph designed to be a replicable and cost effective method of undertaking precision radial velocity measurements. Two versions of RHEA currently exist, one located at the Australian National University in Canberra, Australia (450 - 600nm wavelength range), and another located at the Subaru Telescope in Hawaii, USA (600 - 800 nm wavelength range). Both instruments have a novel fibre feed consisting of an integral field unit injecting light into a 2D grid of single mode fibres. This grid of fibres is then reformatted into a 1D array at the input of the spectrograph (consisting of the science fibres and a reference fibre capable of receiving a white-light or xenon reference source for simultaneous calibration). The use of single mode fibres frees RHEA from the issue of modal noise and significantly reduces the size of the optics used. In addition to increasing the overall light throughput of the system, the integral field unit allows for cutting edge science goals to be achieved when operating behind the 8.2m Subaru Telescope and the SCExAO adaptive optics system. These include, but are not limited to: resolved stellar photospheres; resolved protoplanetary disk structures; resolved Mira shocks, dust and winds; and sub-arcsecond companions. We present details and results of early tests of RHEA@Subaru and progress towards the stated science goals.

We describe the Instrument Control Software (ICS) package that we have built for The Habitable-Zone Planet Finder (HPF) spectrometer. The ICS controls and monitors instrument subsystems, facilitates communication with the Hobby-Eberly Telescope facility, and provides user interfaces for observers and telescope operators. The backend is built around the asynchronous network software stack provided by the Python Twisted engine, and is linked to a suite of custom hardware communication protocols. This backend is accessed through Python-based command-line and PyQt graphical frontends. In this paper we describe several of the customized subsystem communication protocols that provide access to and help maintain the hardware systems that comprise HPF, and show how asynchronous communication benefits the numerous hardware components. We also discuss our Detector Control Subsystem, built as a set of custom Python wrappers around a C-library that provides native Linux access to the SIDECAR ASIC and Hawaii-2RG detector system used by HPF. HPF will be one of the first astronomical instruments on sky to utilize this native Linux capability through the SIDECAR Acquisition Module (SAM) electronics. The ICS we have created is very flexible, and we are adapting it for NEID, NASA's Extreme Precision Doppler Spectrometer for the WIYN telescope; we will describe this adaptation, and describe the potential for use in other astronomical instruments.

We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named “iLocater.” The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 &mu;m), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R~150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use “extreme” adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of low-mass planets using the Doppler technique, iLocater will also advance areas of research that involve crowded fields, line-blanketing, and weak absorption lines.

High-order wavefront correction is not only beneficial for high-contrast imaging, but also spectroscopy. The size of a spectrograph can be decoupled from the size of the telescope aperture by moving to the diffraction limit which has strong implications for ELT based instrument design. Here we present the construction and characterization of an extremely efficient single-mode fiber feed behind an extreme adaptive optics system (SCExAO). We show that this feed can indeed be utilized to great success by photonic-based spectrographs. We present metrics to quantify the system performance and some preliminary spectra delivered by the compact spectrograph.

SCExAO is the premier high-contrast imaging platform for the Subaru Telescope. It offers high Strehl ratios at near-IR wavelengths (y-K band) with stable pointing and coronagraphs with extremely small inner working angles, optimized for imaging faint companions very close to the host. In the visible, it has several interferometric imagers which offer polarimetric and spectroscopic capabilities. A recent addition is the RHEA spectrograph enabling spatially resolved high resolution spectroscopy of the surfaces of giant stars, for example. New capabilities on the horizon include post-coronagraphic spectroscopy, spectral differential imaging, nulling interferometry as well as an integral field spectrograph and an MKID array. Here we present the new modules of SCExAO, give an overview of the current commissioning status of each of the modules and present preliminary results.

We report on the construction and testing of a vacuum-gap Fabry-Perot etalon calibrator for high precision radial velocity spectrographs. The etalon is referenced against hyper fine transitions of rubidium to provide a precise wavelength calibrator for MAROON-X, a new fiber-fed, red-optical, high-precision radial-velocity spectrograph currently under construction for one of the twin 6.5m Magellan Telescopes in Chile. We demonstrate a turnkey system, ready to be installed at any current and next generation radial velocity spectrograph that requires calibration over a wide spectral band-pass. Uncertainties in the position of one etalon line are at the 10 cm s<sup>-1</sup> level in individual measurements taken at 4 Hz. Our long-term stability is mainly limited by aging effects of the spacer material Zerodur, which imprints a 12 cm s<sup>-1</sup> daily drift. However, as the etalon position is traced by the rubidium reference with a precision of &lt;3 cm s<sup>-1</sup> for integration times longer than 10s, we can fully account for this effect at the RV data reduction level.

Optical fibers are a key component for high-resolution spectrographs to attain high precision in radial velocity measurements. We present a custom fiber with a novel core geometry - a 'D'-shape. From a theoretical standpoint, such a fiber should provide superior scrambling and modal noise mitigation, since unlike the commonly used circular and polygonal fiber cross sections, it shows chaotic scrambling. We report on the fabrication process of a test fiber and compare the optical properties, scrambling performance, and modal noise behaviour of the D-fiber with those of common polygonal fibers.

We present the design for a high resolution near-infrared spectrograph. It is fed by a single-mode fiber coupled to a high performance adaptive optics system, leading to an extremely stable instrument with high total efficiency. The optical design is a cross-dispersed Echelle spectrograph based on a white pupil layout. The instrument uses a R6 Echelle grating with 13.3 grooves per mm, enabling very high resolution with a small beam diameter. The optical design is diffraction limited to enable optimal performance; this leads to subtle differences compared to spectrographs with large input slits.

Optical fibres have successfully been used to couple high-resolution spectrographs to telescopes for many years. As they allow the instrument to be placed in a stable and isolated location, they decouple the spectrograph from environmental influences. Fibres also provide a substantial increase in stability of the input illumination of the spectrograph, which makes them a key optical element of the two high-resolution spectrographs of CARMENES. The optical properties of appropriate fibres are investigated, especially their scrambling and focal ratio degradation (FRD) behaviour. In the laboratory the output illumination of various fibres is characterized and different methods to increase the scrambling of the fibre link are tested and compared. In particular, a combination of fibres with different core shapes shows a very good scrambling performance. The near-field (NF) shows an extremely low sensitivity to the exact coupling conditions of the fibre. However, small changes in the far-field (FF) can still be seen. Related optical simulations of the stability performance of the two spectrographs are presented. The simulations focus on the influence of the non-perfect illumination stabilization in the far-field of the fibre on the radial velocity stability of the spectrographs. We use ZEMAX models of the spectrographs to simulate how the barycentres of the spots move depending on the FF illumination pattern and therefore how the radial velocity is affected by a variation of the spectrograph illumination. This method allows to establish a quantitative link between the results of the measurements of the optical properties of fibres on the one hand and the radial velocity precision on the other. The results provide a strong indication that 1ms􀀀1 precision can be reached using a circular-octagonal fibre link even without the use of an optical double scrambler, which has successfully been used in other high-resolution spectrographs. Given the typical throughput of an optical double scrambler of about 75% to 85 %, our solution allows for a substantially higher throughput of the system.

Accurate wavelength calibration is crucial for attaining superior Doppler precision with high resolution spectrographs. Upcoming facilities aim for 10 cm/s or better radial velocity precision to access the discovery space for Earth-like exoplanets. To achieve such precision over timescales of years, currently used wavelength cal- ibrators such as thorium-argon lamps and iodine cells will need to be replaced by more precise and stable sources. The ideal wavelength calibrator would produce an array of lines that are uniformly spaced, narrower than the spectrograph resolution, of equal brightness, cover the entire wavelength range of the spectrograph, and whose frequencies do not change with time. Laser frequency combs are an extremely accurate and stable, albeit technically challenging and costly, option that has received much attention recently. We present an alter- native method that uses a Fabry-Perot (FP) etalon illuminated by a white light source to produce a comb-like spectrum over a wide wavelength range. Previous work focused on the development of passively stabilized FP etalons for wavelength calibration. We improve on this method by locking the etalon to an atomic transition,
the frequency of which is known to &lt; 2 x 10<sup>-11.7</sup> We use a diode laser to observe both the rubidium (Rb) D<sub>2</sub> transition at 780 nm and the etalon transmission spectrum. Saturated absorption spectroscopy is used to resolve the Rb hyperfine lines and precisely determine their locations. Since the etalon spectrum is probed with the same laser, the etalon can be locked by ensuring that one of its transmission peaks coincides with a particular Rb hyperfine peak (via either temperature tuning or a piezoelectric transducer incorporated into the etalon). By measuring the frequency of one etalon peak directly via comparison with the Rb, we remove any drifts or aging effects of the etalon that could cause problems for passively stabilized etalon references. We demonstrate a locking precision that is equivalent to a Doppler precision of 3 cm/s RMS.
Our setup is simple and robust, can be used with various etalons, and works in the infrared as well as the visible part of the spectrum. The combination of low cost, ease of use, and high precision make this calibration system an attractive option for new spectrographs and as a retrofit for existing facilities.

We present the design concept of the wavelength calibration system for the Habitable-zone Planet Finder instrument (HPF), a precision radial velocity (RV) spectrograph designed to detect terrestrial-mass planets around M-dwarfs. HPF is a stabilized, fiber-fed, R~50,000 spectrograph operating in the near-infrared (NIR) z/Y/J bands from 0.84 to 1.3 microns. For HPF to achieve 1 m s<sup>-1</sup> or better measurement precision, a unique calibration system, stable to several times better precision, will be needed to accurately remove instrumental effects at an unprecedented level in the NIR. The primary wavelength calibration source is a laser frequency comb (LFC), currently in development at NIST Boulder, discussed separately in these proceedings. The LFC will be supplemented by a stabilized single-mode fiber Fabry-Perot interferometer reference source and Uranium-Neon lamp. The HPF calibration system will combine several other new technologies developed by the Penn State Optical-Infrared instrumentation group to improve RV measurement precision including a dynamic optical coupling system that significantly reduces modal noise effects. Each component has been thoroughly tested in the laboratory and has demonstrated significant performance gains over previous NIR calibration systems.

The Habitable-Zone Planet Finder is a stabilized, fiber-fed, NIR spectrograph being built for the 10m Hobby- Eberly telescope (HET) that will be capable of discovering low mass planets around M dwarfs. The optical design of the HPF is a white pupil spectrograph layout in a vacuum cryostat cooled to 180 K. The spectrograph uses gold-coated mirrors, a mosaic echelle grating, and a single Teledyne Hawaii-2RG (H2RG) NIR detector with a 1.7-micron cutoff covering parts of the information rich z, Y and J NIR bands at a spectral resolution of R∼50,000. The unique design of the HET requires attention to both near and far-field fiber scrambling, which we accomplish with double scramblers and octagonal fibers. In this paper we discuss and summarize the main requirements and challenges of precision RV measurements in the NIR with HPF and how we are overcoming these issues with technology, hardware and algorithm developments to achieve high RV precision and address stellar activity.

A key avenue to improving the precision of radial velocity measurements is by using photonic devices to collect the
light from the focal plane and delivering the beams to the slit of spectrograph via a single-mode fiber. Single-mode
fibers have the favorable property that they allow light to propagate in a single energy distribution characterized by a
Gaussian shape with a flat wavefront which is temporarily stable and independent of changes to the injection. These
properties mean that the point spread function delivered to the input slit of a spectrograph is highly stable with time
and independent of changes to the injection which is currently a key limitation to precision radial velocity
measurements and known as "Modal Noise". Further light delivery via single-mode fibers is the key requirement to
realize long baseline interferometers such as the Optical Hawaiian Array for Nanoradian Astronomy.
Injecting into single-mode fibers efficiently is inherently difficult because it requires closely matching the intensity
and wavefront of the focused beam to that supported by the fiber. The atmosphere is currently the key roadblock to
efficient injection. However, extreme adaptive optics systems such as Subaru Coronagraphic Extreme Adaptive
Optics (SCExAO) system currently being commissioned will enable high order wavefront correction and make
efficient coupling into single-mode fibers possible. In addition, pupil apodization optics used for coronagraphy,
known as phase induced amplitude apodization lenses also present in the SCExAO instrument, allow for close
matching of the intensity distributions.
We report on the progress and lessons learnt on developing an efficient single-mode injection unit within the
SCExAO instrument. As part of the PANDORA project we aim to use this injection and combine it with several
other photonic technologies to enable high precision radial velocity measurements in new and innovative ways.

The detection of Earth analogs with radial velocity requires extreme Doppler precision and long term stability.
Variations in the illumination of the slit and of the spectrograph optics occur on time scales of seconds and
minutes, primarily because of guiding, seeing and focusing. These variations yield differences in the instrumental
profile (IP). In order to stabilize the IP, we designed a fiber feed for the Hamilton spectrograph at Lick and for
HIRES at Keck. Here, we report all results obtained with these fiber scramblers. We also present the design of
a new double scrambler/pupil slicer for HIRES at Keck.

The detection of earth-like exoplanets with the Doppler technique requires extreme precision spectrographs stable over
timescales of years. The precision requirement of 10 cm/s is equivalent to a relative uncertainty of 3x10<sup>-10</sup>, and, with the typical dispersion of the Echelle spectrographs used for this purpose, translates to a shift of a few nanometers of the spectrum on the detector. Consequently, the instrument must be well understood and optimized in every component and detail. We describe the Yale Doppler diagnostic facility (YDDF), a dedicated bench mounted Echelle spectrograph in
our lab at Yale University, which will be used to systematically study the influence of different components at this
precision level. The spectrograph bench allows for a flexible optical configuration, high resolution and sampling, and
wide spectral coverage. Further, we incorporated a turbulence and guiding simulator to realistically reproduce the
situation at the telescope, enabling end-to-end tests of important parameters.

A multiplexed moderate resolution (R = 34,000) and a single object high resolution (R = 90,000) spectroscopic facility
for the entire 340 - 950nm wavelength region has been designed for Gemini. The result is a high throughput, versatile
instrument that will enable precision spectroscopy for decades to come. The extended wavelength coverage for these
relatively high spectral resolutions is achieved by use of an Echelle grating with VPH cross-dispersers and for the R =
90,000 mode utilization of an image slicer. The design incorporates a fast, efficient, reliable system for acquiring targets
over the7 arcmin field of Gemini. This paper outlines the science case development and requirements flow-down process
that leads to the configuration of the HIA instrument and describes the overall GHOS conceptual design. In addition, this
paper discusses design trades examined during the conceptual design study instrument group of the Herzberg Institute of
Astrophysics has been commissioned by the Gemini Observatory as one of the three competing organizations to conduct
a conceptual design study for a new Gemini High-Resolution Optical Spectrograph (GHOS). This paper outlines the
science case development and requirements flow-down process that leads to the configuration of the HIA instrument and
describes the overall GHOS conceptual design. In addition, this paper discusses design trades examined during the
conceptual design study.

The detection of Earth analogs with radial velocity requires long-term precision of 10 cm/s. One of the factors
limiting precision is variation in instrumental profile from observation to observation due to changes in the
illumination of the slit and spectrograph optics. Fiber optics are naturally efficient scramblers. Our research is
focused on understanding the scrambling properties of fibers with different geometries. We have characterized
circular and octagonal fibers in terms of focal ratio degradation, near-field and far-field distributions. We have
characterized these fibers using a bench-mounted high-resolution spectrograph: the Yale Doppler Diagnostics
Facility (YDDF).

CHIRON is a fiber-fed Echelle spectrograph with observing modes for resolutions from 28,000 to 120,000, built
primarily for measuring precise radial velocities (RVs). We present the instrument performance as determined during
integration and commissioning. We discuss the PSF, the effect of glass inhomogeneity on the cross-dispersion prism,
temperature stabilization, stability of the spectrum on the CCD, and detector characteristics. The RV precision is
characterized, with an iodine cell or a ThAr lamp as the wavelength reference. Including all losses from the sky to the
detector, the overall efficiency is about 6%; the dominant limitation is coupling losses into the fiber due to poor guiding.

ARGOS the Advanced Rayleigh guided Ground layer adaptive Optics System for the LBT (Large Binocular Telescope)
is built by a German-Italian-American consortium. It will be a seeing reducer correcting the turbulence in the lower
atmosphere over a field of 2' radius. In such way we expect to improve the spatial resolution over the seeing of about a
factor of two and more and to increase the throughput for spectroscopy accordingly. In its initial implementation,
ARGOS will feed the two near-infrared spectrograph and imager - LUCI I and LUCI II.
The system consist of six Rayleigh lasers - three per eye of the LBT. The lasers are launched from the back of the
adaptive secondary mirror of the LBT. ARGOS has one wavefront sensor unit per primary mirror of the LBT, each of the
units with three Shack-Hartmann sensors, which are imaged on one detector.
In 2010 and 2011, we already mounted parts of the instrument at the telescope to provide an environment for the main
sub-systems. The commissioning of the instrument will start in 2012 in a staged approach. We will give an overview of
ARGOS and its goals and report about the status and new challenges we encountered during the building phase. Finally
we will give an outlook of the upcoming work, how we will operate it and further possibilities the system enables by
design.

ARGOS, the laser-guided adaptive optics system for the Large Binocular Telescope (LBT), is now under construction at
the telescope. By correcting atmospheric turbulence close to the telescope, the system is designed to deliver high
resolution near infrared images over a field of 4 arc minute diameter. Each side of the LBT is being equipped with three
Rayleigh laser guide stars derived from six 18 W pulsed green lasers and projected into two triangular constellations
matching the size of the corrected field. The returning light is to be detected by wavefront sensors that are range gated
within the seeing-limited depth of focus of the telescope. Wavefront correction will be introduced by the telescope's
deformable secondary mirrors driven on the basis of the average wavefront errors computed from the respective guide
star constellation. Measured atmospheric turbulence profiles from the site lead us to expect that by compensating the
ground-layer turbulence, ARGOS will deliver median image quality of about 0.2 arc sec across the JHK bands. This will
be exploited by a pair of multi-object near-IR spectrographs, LUCIFER1 and LUCIFER2, with 4 arc minute field already
operating on the telescope. In future, ARGOS will also feed two interferometric imaging instruments, the LBT
Interferometer operating in the thermal infrared, and LINC-NIRVANA, operating at visible and near infrared
wavelengths. Together, these instruments will offer very broad spectral coverage at the diffraction limit of the LBT's
combined aperture, 23 m in size.

We describe the optical design of a calibration unit for the off-axis laser guide stars at the Large Binocular Telescope's ARGOS facility. Artificial stars with the desired wavefront are created using a computer generated hologram.

ARGOS is the Laser Guide Star adaptive optics system for the Large Binocular Telescope. Aiming for a wide field
adaptive optics correction, ARGOS will equip both sides of LBT with a multi laser beacon system and corresponding
wavefront sensors, driving LBT's adaptive secondary mirrors. Utilizing high power pulsed green lasers the artificial
beacons are generated via Rayleigh scattering in earth's atmosphere. ARGOS will project a set of three guide stars above
each of LBT's mirrors in a wide constellation. The returning scattered light, sensitive particular to the turbulence close to
ground, is detected in a gated wavefront sensor system. Measuring and correcting the ground layers of the optical
distortions enables ARGOS to achieve a correction over a very wide field of view. Taking advantage of this wide field
correction, the science that can be done with the multi object spectrographs LUCIFER will be boosted by higher spatial
resolution and strongly enhanced flux for spectroscopy. Apart from the wide field correction ARGOS delivers in its
ground layer mode, we foresee a diffraction limited operation with a hybrid Sodium laser Rayleigh beacon combination.

Astronomical optics are often exposed to moisture and dust in observatory environments, which frequently compromises
their high-performance coatings. Suitable protective layers to resist dust and moisture accumulation would be extremely
advantageous, but have received scant attention thus far. Hydrophobic and scratch-resistant coatings, developed
primarily for opthalmic use, exhibit several attractive properties for astronomical optics. We examine the properties of
one such coating and its applicability to astronomical mirrors and lenses. This includes efficiency of dust removal,
abrasion resistance, moisture resistance, ease of stripping, and transmission across a wide wavelength range.

The Large Binocular Telescope Interferometer (LBTI) has been developed and tested and is almost ready to be installed
to LBT mount. In preparation for installation, testing of the beam combination and phasing of the system have been
developed. The testing is currently in progress.
The development of a telescope simulator for LBTI has allowed verification of phasing and alignment with a broad band
source at 10 microns<sup>2</sup>. Vibration tests with the LBTI mounted to the LBT were carried out in July 2008, with both
seismic accelerometers and an internal optical interferometric measurement. The results have allowed identification of
potential vibration sources on the telescope. Plans for a Star Simulator that illuminates each LBT aperture at the prime
focus with two artificial point sources derived from a single point source via fiber optics are presented. The Star
Simulator will allow testing of LBTI with the telescope and the adaptive secondaries in particular. Testing with the Star
Simulator will allow system level testing of LBTI on the telescope, without need to use on-sky time. Testing of the Star
Simulator components are presented to verify readiness for use with the LBTI.

Small telescopes coupled to high resolution spectrometers are powerful tools for Doppler planet searches. They allow for
high cadence observations and flexible scheduling; yet there are few such facilities. We present an innovative and
inexpensive design for CHIRON, a high resolution (R~80.000) Echelle spectrometer for the 1.5m telescope at CTIO.
Performance and throughput are very good, over the whole spectral range from 410 to 870nm, with a peak efficiency of
15% in the iodine absorption region. The spectrograph will be fibre-fed, and use an iodine cell for wavelength
calibration. An image slicer permits a moderate beam size. We use commercially available, high performance optical
components, which is key for quick and efficient implementation. We discuss the optical design, opto-mechanical
tolerances and resulting image quality.

The detection of Earth analogues requires extreme Doppler precision and long term stability in order to measure tiny reflex velocities in the host star. The PSF from the spectrometer should be slowly varying with temperature and pressure changes. However, variations in the illumination of the slit and of the spectrograph optics occur on time scales of seconds, primarily because of guiding errors, but also on timescales of minutes, because of changes in the focus or seeing. These variations yield differences in the PSF from observation to observation, which are currently limiting the Doppler precision. Here, we present the design of a low cost fiber optic feed, FINDS, used to stabilize the PSF of the Hamilton spectrograph of Lick observatory along with the first measurements that show dramatic improvement in stability.

Effective calibration procedures play an important role for the efficiency and performance of astronomical
instrumentation. We report on the calibration scheme for ARGOS, the Laser Guide Star (LGS) facility at the LBT. An
artificial light source is used to feign the real laser beacons and perform extensive testing of the system, independent of
the time of day and weather conditions, thereby greatly enhancing the time available for engineering. Fibre optics and
computer generated holograms (CGHs) are used to generate the necessary wavefront. We present the optomechanical
design, and discuss the expected accuracy, as well as tolerances in assembly and alignment.

Laser guide star adaptive optics and interferometry are currently revolutionizing ground-based near-IR astronomy, as
demonstrated at various large telescopes. The Large Binocular Telescope from the beginning included adaptive optics in
the telescope design. With the deformable secondary mirrors and a suite of instruments taking advantage of the AO
capabilities, the LBT will play an important role in addressing major scientific questions. Extending from a natural guide
star based system, towards a laser guide stars will multiply the number of targets that can be observed. In this paper we
present the laser guide star and wavefront sensor program as currently being planned for the LBT. This program will
provide a multi Rayleigh guide star constellation for wide field ground layer correction taking advantage of the multi
object spectrograph and imager LUCIFER in a first step. The already foreseen upgrade path will deliver an on axis
diffraction limited mode with LGS AO based on tomography or additional sodium guide stars to even further enhance
the scientific use of the LBT including the interferometric capabilities.

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